Load-supporting building tile



C. II. BIRDSI: IA

LOAD SUPPORTING BUILDING TILE. AvPLlcAloN miv M1623, 1918.

Lg Mmm-Imp@ 1142, w23,

' ATTORNEY.

v Patented Sept. 12, 1922:;

UNITED" STAT Es PArlazN'r oFF-ICE.

CHARLES R. BIRD-SEY, 0F HISIDALE, ILLINOIS, ASSIGNOR, BY MESNE'ASSIGNMENTS, TO UNITED STATESGYPSUM COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION or rumors.

/ d. applicati@ med August 23, 191s. serial No. 251,115.

To all lwhom it may concern:

Be is'known that I, CHARLES R. Braosnr, a citizen of the United States, residing lat Hinsdale,`in the county of Dupage and State of Illinois, have invented certain newand useful Improvements in Load- Supporting Building Tiles, of which the following `is a descript1on.

This invention relates to the construction of tiles for building purposes and more particularlyvto load supporting building tiles, such as used in roofs.

It is an object of this invention to provide a long span reinforced roof tile of light weight by employing calcined gypsum for its body. It is a further object of this invention to so form the tile as to be economical in the amount of gypsum employed and arrange the reinforcement to afford the greatest strength in proportion toits weight. It is a further object of this invention to so construct the tile that without defacement it maybe readily ascertained that the proper reinforcements are embedded in its body.

While the preferred forms. of this invention are illustrated in the accompanying sheet of drawing, yet m'inor detail changes may be made without departing from the scopethereof. A

In the drawing, i

Figure 1 is a top plan view of one form of this invention, with parts of the top Eroken away to show the reinforcing memers.

'Figure 2 is a view in section taken on the line 2 2, Figure l. i

Figure 3 is a view in section taken on the line 3 3, Figure 1. i

Figure 4v is a View in section line. 4 4, Figure 1. Y

Figure 5 is a top plan view of another form of this invention, with part of the top broken away to show a modified form of remforcement.

Figures 6, 7 and 8 are lviews in'section taken on lines 6 6, 7 7,land 8 8, respectively, on Figure 5.

Figure 9 is a view in end elevation.

Figure 10, a similar view, illustrating a modication.

In 4the constructing of long span gypsum tile, that is a tile of from four to eight feet in length and from one to two feet in width, there are tWo things that must be considered. The crushing, or breaking taken on the strength of gypsum products is verylargely increased as the density and weight of'the product is increased and the nature of calcined gypsum causes it to expand as it sets, in this latter respect differing from other materials of supposedly similar character which shrink upon setting and the exclusion of the moisture. The density and weight of a vgypsum product is limited by the quantity-of water or liquid required to cause it to properly pour in the molds, as the ratio of liquid and gypsum is substantiallymaintained, and a long span roof tile when supported only at its ends must be reinforced to sustain the load and unusual or occasional strains. To reinforce the tile for this purpose it is preferable to employ longitudinal rods positioned in lower portlon of thetile below the medial plane and firmly anchored at each end because, owino to its nature gypsum does not have sufficient bond value strength to properly adhere to a reinforcing rod unless it is firmly anchored at its ends. As long span gypsum roof tile is a beam in which .the gypsum above the medial plane is the compression member and the reinforcing rods below the medial plane the tension member, the strength of the tile can be regulated by using steel rods and gypsum in proper proportions to withstand the strains set up in the tile by any predetermined load. Tiles of this character as contemplated by this invention are formed in moulds in which the ends of the reinforcing rods forming the tension members are anchored in any preferable manner below the medial plane of the tile and with the rods thus placed, the expanding of the gypsum longitudinally in setting below the medial plane is arrested. The expanding of the tile in the upper portion goes on causing a bowing or crowning of the surface in a longitudinal direction. While it is not necessary to reinforce the slab of gypsum above the medial line,

` it is preferable to place therein a number of rods crossing each other to form a mat which not only reinforces this portion but the rods arrest the expanding and crowning action of the gypsum above the medial plane.

The preferred form of the tile constructed` in accordance with this invention', as illustrated, comprises an upper surface in the form of a flat slab 1 of gypsum having depending edge portions 2 and 3 on the sides and ends of uniform widthl and depth. l Two sum surrounding the rods is much greater than the bond value of the gypsum to the rods unless so anchored. The bending oftheJ ends of the rods upward and then back for a substantial distance above the medial .plane a-iford the preferred manner for anchoring the ends of lthe reinforcing rods.

The width of the tile being from twelve to twenty inches, the bowing or crowning in a transverse direction owing to the expansion ofthe gypsum as it sets is not ordinarilA so important to a structure of the kind.. t is preferred to prevent this crowning in both l longitudinal and transverse directions of the upper .surface of the slab l above the medial plane by embedding a series of transverse rods 5., .extending above the rods y4 and terminating adjacent the sides resting on a series of longitudinal rods 6, extending from end to end, which form .a mat within the slab l and accomplish both a reinforcement and arrest the uneven expansion of the gypsum in setting. Figures l to 4 inclusive lllustrate the transverse rods 5 resting on the longitudinal .rods v6 and secured to each other, as by spot welding. Figures 5 to 8 inclusive illustrate the rods interwoven in which the transverse rods lie substantially in the plane of the bent back portions ofthe ends of the rods 4 and may be spot welded, if desired.

Inspection openings x7 are, rovided at each end of the tile, as shown in igure 9., which uncover a portion of the vertically bent fend of each reinforcing rod 4, iand Figure 10 shows additional inspection openings 8 uncovering the ends of the longitudinal rods 6 forminga part of the mat in thesla'b `1, and by these openings 'the rods .may be readily seenand their presence assured. This is of great importance as otherwisel an inspection of the -tile would not in any way disclose the fact that the rods were inpplace, or had been for any. reason omitted which would practically destroy the load carrying power of the tile, and in a tile of this character might result in serious damage and loss. V

`When these tiles are in position upon a roof it is desirable to close the joints between the various units to prevent Ithe'tar or other material that may be placed over the tile .in completing the roof from running down between them. This is prevented by chamfering, notching or otherwise recessing the longitudinal upper edge of the tile, as at 9, to form pockets between the tiles to be filled with a suitable gypsum mortar prepared for that purpose.

What claim is:

1. A load supporting tile having depending 'edge portions at opposite sides thereof, continuous reinforcing rods in the depend ing edge portions extending longitudinally thereof below the medial plane of the tile and having end ,portions extending upwardly and then backwardly horizontally a substantial distance in the main body portion of the tile, and transversely extending reinforcing means `embedded in the tile above the medial plane thereof and extending into the edge port-ions of the tile above 4 said depending edge portions.

2. A load supportingvbuilding tile having depending edge portions'at opposite sides thereof, continuous reinforcing rods in .the depending edgel portions extending longitudinally thereof below the medial plane ofv the tile and having end portions extending upwardly and thence backwardly horizontally in the main body portion'of the tile .above the medial Aplane thereof, and transverse rods embedded in the tile above the medial plane thereof in the horizontal planeof the backwardly extending end portions of the first mentioned reinforcing rods.

3. A building tile having an inspection opening extending from its exterior inwardly thereof, in combination with reinforcing means embedded vin the tile and terminating short of the exterior of the tile,

said reinforcing means extending to said sight opening.

4. A building tile havlng inspection openings extending from the exterior inwardlylatopposite ends thereof, in combination with longitudinally extending reinforcing means embedded in the tile and vterminating at its ends shortof the exterior of th'e tile, theend portions of said reinforcing means extending to and disclosed in said sight openings.

5. A building tile having longitudinally extending reinforcing rods embedded therein, said rods .having angularly disposed end portions anchored 1n the .tile and said tile being provided with inspection sight openings extending inwardly from the. exterior ofthe tile tothe angularly disposed portions of 'the reinforcing rods.

In testimony whereof, I have hereunto signed my name in the scribing witnesses.

CHARLES R. BIRDSEY.

Witnesses JOHN W. HILL. CHARLES I. Cone.

presence of two subi 

